1. Field of the Invention
This invention relates to a lens assembly, more particularly to a lens assembly that guides emission of light sideways.
2. Description of the Related Art
FIG. 1 illustrates a conventional lens that defines a central axis 10, and that includes a funnel-shaped portion 11, and a cup portion 12 opposite to the funnel-shaped portion 11. The funnel-shaped portion 11 has reflecting and refracting surfaces 111, 112. The cup portion 12 confines a light source 1.
When the light source 1 emits light, a portion of the light, as indicated by arrow (X), is refracted by the cup portion 12, is internally reflected by the reflecting surface 11 of the funnel-shaped portion 11, and is refracted by the refracting surface 112 of the funnel-shaped portion 11 such that the light exits the funnel-shaped portion 11 in lateral directions relative to the central axis 10. Moreover, another portion of the light, as indicated by arrow (Y), is refracted by the cup portion 12 such that the light exits the cup portion 12 in lateral directions relative to the central axis 10.
The aforementioned conventional lens is disadvantageous in that a small portion of the light emitted by the light source 1 that forms a relatively small angle with respect to the central axis 10, passes through the reflecting surface 111 of the funnel-shaped portion 11, which results in a light spot. Moreover, the reflecting and refracting surfaces 111, 112 of the funnel-shaped portion 11 of the lens intersect each other to form an acute angle therebetween. As such, the conventional lens has a fragile structure.